Buzz
The northern lights are elusive for many, mainly visible in the winter months in the higher latitudes of the Northern Hemisphere. But even rarer than that are the anti-auroras, or black auroras.
According to Live Science, an aurora enthusiast named Todd Salat captured a photo of one on November 22, around 4:00 a.m. in south-central Alaska. The photographer described the anti-aurora as resembling the letter E, shifting shapes and drifting 'overhead on its back,' like a creature with its legs in the air. The spectacle lasted just a few minutes.
So, what exactly is an anti-aurora? The European Space Agency (ESA) explains that it consists of dark patches in the aurora borealis, which can appear as black circles, swirls, or formless masses. This rare event occurs when electrons escape into space through openings in the ionosphere, the opposite of a typical aurora, where electrons descend from space and collide with particles in the ionosphere to create colorful lights.
Anti-auroras were first identified in the late 1990s. It wasn't until 2001 that scientists understood how they work, after four ESA satellites flew over a black aurora, detecting small regions known as positively-charged electric potential structures in the upper atmosphere.
Even with this discovery, the full nature of black auroras remained unclear. A 2015 study provided more insight, using over ten years of ESA satellite data to uncover the mechanism behind these structures. Researchers found that they form when auroras release plasma, creating 'ionospheric cavities' in the upper atmosphere, while the magnetosphere shifts due to pressure from solar storms.
The conditions must be just right for this phenomenon to occur. While the northern lights can last anywhere from minutes to hours, anti-auroras are much shorter, lasting only about 10 to 20 minutes each time.
If you're seeking affordable spots to view the northern lights, check out these destinations. Recent increases in solar activity have led to stunning light displays, and scientists predict the peak will occur around 2026 or 2027.
